Method and apparatus for contouring composite pre-preg articles

ABSTRACT

A forming tool and method for its use with flat pre-preg composite laminate assemblies which incorporates a mandrel segmented into multiple forming blocks, the forming blocks sized to receive a draped composite laminate assembly with all portions of the composite laminate assembly spaced from a shaping surface on each block. A spline plate engages the shaping surface of the forming blocks to provide a neutral axis for maintaining the entire composite laminate assembly in tension during forming. In the exemplary embodiments, the draped composite laminate assembly is formed to the forming blocks from the flat composite laminate assembly and maintained in contact with the forming blocks using a vacuum bag. The mandrel forming blocks are then displaced to a desired curvature on the spline plate.

REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 11/769,082 filed on Jun. 27, 2007 now U.S. Pat. No. 8,118,959entitled METHOD AND APPARATUS FOR CONTOURING COMPOSITE PRE-PREG ARTICLEShaving common inventors and a common assignee with the presentapplication.

BACKGROUND INFORMATION

1. Field

This invention relates generally to the forming of composite structuresand more particularly to a forming method and tooling for single ormultiple axis forming of a flat epoxy pre-impregnated laminate(pre-preg) charge using a flexible mandrel maintaining the entire crosssection of the mandrel and part under tension during the curve formingoperation.

2. Background

Replacement of machined, cast, forged or stamped metallic structuralelements such as aluminum wing ribs, in an aerospace industry example,with composite structures is becoming highly desirable for weightreduction and performance enhancement of structural assemblies. For thecomposite wing rib example, without limitation, ribs may be similar tobuilt-up aluminum ribs, using separate webs, chords and stiffeners. Allof the parts may be produced primarily from epoxy pre-impregnatedcomposite tape which typically is placed manually on a predetermineshaped mandrel followed by curing within an autoclave.

The two fundamental approaches presently in the art are to assemblecomposite laminate onto a tooling form in a predetermined manner in itsfinal shape on the cure mandrel, or assemble in a predetermined manner aflat charge of composite laminate, mechanically form it to shape, andthen cure it.

Forming of composite elements which have variable contour with localareas having a contour as tight as 300 inch radius currently requiresmanual layup a shaped mandrel. At a typical rate of one pound per hourper employee, manual laminate assembly of the large structural elementsis not an economical approach for full production applications.Automated lay-up of composite structural elements directly on curemandrels is possible with modified fiber placement machines. However,such an approach requires specific machine development with associatedvery high capital investment.

It is therefore desirable to assemble in a predetermined manner flatcomposite laminate assemblies or charges and form them to shape. Flatcharges are typically manufactured using composite tape automationmethods and these machines are very cost effective at producing flatcharges. Capability is readily available with current manufacturingprocesses to drape form flat charges to a channel shape on a flexiblemandrel and then cure the mandrel. However, this process is suitable forlarge radius bends only. At radii of 1500 inches or less, there may beproblems of causing buckles in the pre-preg composite laminate assembly.

It is also therefore desirable to provide a method and tooling forshaping and cure of flat charge layups of prepreg materials with singleor multiple centers of curvature which precludes buckling of compositeassembly.

SUMMARY

The embodiments disclosed herein provide a forming tool and method forits use with flat impregnated laminate assemblies or charges whichincorporate a mandrel segmented into multiple forming blocks, theforming blocks sized to receive a draped composite laminate assemblywith all portions of the composite laminate assembly spaced from ashaping surface on each block. A spline plate engages the shapingsurface of the forming blocks. In the exemplary embodiments, the drapedcomposite laminate assembly is formed to the forming blocks from theflat composite laminate assembly and maintained in contact with theforming blocks using a vacuum bag. The mandrel forming blocks are thendisplaced to a desired curvature. The curvature is induced by employingthe spline plate in a saddle onto which the segmented mandrel is placed.Upon relaxation of the segmented forming blocks in the mandrel onto thesaddle, the desired curvature is induced.

In one embodiment providing multiple axis forming, the mandrel issegmented into a plurality of contiguously mounted forming blocks sizedto receive a draped composite laminate assembly with all portions of thecomposite laminate assembly spaced from a first shaping surface and asecond shaping surface on each block. The mandrel incorporates a cablerestraining the forming blocks on a neutral axis with protuberances forthe second shaping surface to offset the neutral axis. A saddle tool hasa first spline plate with a first center of curvature receiving thefirst shaping surface of the forming blocks and a second spline platewith a second center of curvature receiving the second shaping surfaceon the second spline plate. A vacuum bag maintains the draped compositelaminate assembly in contact with the forming blocks and a relaxabletensioning cable urges the forming blocks into mutual contact in a firsttensioned condition for initially receiving the draped compositelaminate assembly. The tension cable is then relaxed to a releasedcondition allowing the forming blocks to expand to a desired curvatureon the spline plates of the saddle tool.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the embodiments of thedisclosure will be better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1A is an end view of an embodiment of a flexible mandrel withspline plate and a flat Composite laminate assembly formed over amandrel cross-section;

FIG. 1B is a side view of the embodiment of FIG. 1A;

FIG. 2A is an end view of the embodiment of FIG. 1A after flexing of themandrel and spline plate;

FIG. 2B is a side view of the flexed embodiment of FIG. 2A;

FIG. 3A is an end view of exemplary support tooling for operation of theflexible mandrel with spline plate showing initial insertion of a flatcomposite laminate assembly;

FIG. 3B is a side midline section view of the exemplary tooling andcomposite laminate assembly of FIG. 3A;

FIG. 4A is an end view showing the draped composite laminate assemblysupported by the vacuum bag on the mandrel;

FIG. 4B is a side semi-section view of the supported draped compositelaminate assembly of FIG. 4A;

FIG. 5A is an end view showing the formed composite laminate assembly;

FIG. 5B is a side semi-section view of the formed composite laminateassembly of FIG. 5A;

FIG. 6 is an end view of the transfer tool receiving the formedcomposite laminate assembly;

FIG. 7 is an end view of the inverted cure mandrel in position formating with the formed composite laminate assembly;

FIG. 8 is an end view of the inverted cure mandrel with the formedcomposite laminate assembly in place;

FIG. 9 is an end view of the cure mandrel with the cured compositelaminate assembly;

FIG. 10A is an end view of the cured composite laminate assembly showingthe symmetrical part line;

FIG. 10B is a partial side view of the cured composite laminateassembly;

FIG. 11A is an isometric layout of an exemplary tooling line forperforming the exemplary method;

FIG. 11B is a flow chart for an exemplary manufacturing flow employingthe tooling line of FIG. 11A for part forming.

FIG. 12A is an isometric view of an alternative exemplary compositestructural assembly;

FIG. 12B is a section view of the composite structural assembly of FIG.12A;

FIG. 13 is an end view showing a composite laminate assembly layup forthe composite structural assembly of FIGS. 12A and B;

FIG. 14 is an end view of a first alternative composite laminateassembly layup for the composite structural assembly of FIGS. 12A and B;

FIG. 15 is an end view of a second alternative composite laminateassembly layup for the composite structural assembly of FIGS. 12A and B;

FIG. 16 is an end view of a second embodiment of a flexible mandrel andsupport tooling arrangement for forming a multiple axis of curvature;

FIG. 17 is a side view of the second embodiment of a flexible mandreland support tooling arrangement for forming a multiple axis ofcurvature;

FIG. 18 is an isometric view of the second embodiment;

FIG. 19 is a detailed view of the flexible mandrel elements for thesecond embodiment; and,

FIG. 20 is an exemplary formed structural part from the secondembodiment tooling;

FIG. 21 is a flow diagram of aircraft production and servicemethodology; and,

FIG. 22 is a block diagram of an aircraft.

DETAILED DESCRIPTION

The embodiments described herein employ a segmented flexible mandrelreceiving a flat composite laminate assembly for shaping and engaging aspline plate displaced from the composite laminate assembly radiallyinward with respect to the center of curvature and providing a neutralaxis to maintain the entire composite laminate assembly in tensionduring shaping. FIG. 1A shows in end view the mandrel 10 engaging aspline plate 12 with a flat composite laminate assembly 14 (shown in itsinitial configuration in phantom 12′) engaging the outer surface 16 ofthe mandrel and draped around sides 18 of the mandrel as will bedescribed in greater detail subsequently. The composite laminateassembly for the embodiment shown is for forming rib cords in anaircraft structure. For the embodiment shown, the layup has interruptedzero plies to assist in forming. FIG. 1B shows in side view thecomposite laminate assembly extending around the side surface of themandrel which is segmented into forming blocks (with exemplary segmentslabeled as elements 10 a, 10 b and 10 c) engaging the spline plate.

FIGS. 2A and 2B show the mandrel in a formed position about center ofcurvature designated by direction arrow 20. The radius of curvatureshown in the drawing is constant but for alternative embodiments variesalong the length of the segmented mandrel with collections of segmentsforming varying radii of curvature. The exemplary rib cord web 22 andflange 24 can be seen with a part line 25 for left hand and right handparts. As shown in the figures, the spline plate is displaced inwardfrom all elements of the draped composite laminate assembly contactingthe forming blocks on a shaping surface 11 and providing a neutral axis.The mandrel segments expand in response to the curvature of the splineplate maintaining the entire composite laminate assembly in tension forforming.

FIGS. 3A and 3B show an exemplary first embodiment of a support andforming tooling for the mandrel 10 and spline plate 12 and a method forforming the desired composite parts will be described beginning withthese figures. A tray 28 is employed to receive the flat compositelaminate assembly 14′ which has been laid up with the desired plystructure using Flat Tape Laminating Machine (FTLM), compositelaminating machine or Composite Spar and Stringer ReciprocatingLaminator (CSSRL) or similar lay up machines known in the art. Anelastomeric sheet 29 is draped into the tray 28 prior to inserting theflat composite laminate assembly for use as will be described in greaterdetail subsequently. Strip heaters 30 are attached to the tray bottomfor heating of the flat composite laminate assembly in the tray therebyreducing total resin system viscosity within the composite assembly tofacilitate conformal forming of the flat laminate. The spline plate 12extends beyond the lateral extent of the mandrel forming blocks andincorporates pyramid seals 32 which compressively engage downward on theelastomeric sheet 29 as a vacuum seal. Movable actuators in the form ofretractable support rods 34 are mounted to the spline plate and a cordcontour tool 36 provides a surface contour for matching to the splineplate 12 to impart the desired contour. While a contour tool is employedin the embodiment shown, alternative embodiments may employ a greaternumber of support rods at closer spacing with a thicker spline plate todirectly impart the contour to the plate.

The flat composite laminate assembly 14′ is heated to formingtemperature using the strip heaters 30 and the mandrel 10 is lowered (oralternatively, the tray is raised) to engage the composite laminateassembly on the outer surface 16 of the mandrel as shown in FIGS. 4A and4B. Vacuum is drawn urging the Elastomeric sheet 29 to adopt the contourof the mandrel 10 draping the flat composite laminate assembly 14 ontothe sides of the mandrel 10.

The mandrel 10 is then lifted from the tray 28 by retraction of thesupport rods 34 which also engages the spline plate 12 with the contourtool 36 as shown in FIGS. 5A and 5B. The individual segments or formingblocks (10 a, 10 b as exemplary) of the mandrel displace in a mannerconsistent with the induced curvature of the spline plate forming thecomposite laminate assembly 14 which is held in place by the evacuatedelastomeric sheet. Alternative curvatures are obtained by use ofdifferent contour tools or for the embodiment described employingactuators only by programming the retraction length of the variousactuators to achieve the desired curvature of the spline plate.

FIG. 6 shows a transfer tool 38 which is inserted under the mandrelsupport tooling to received the formed composite laminate assembly 14.For the embodiment shown, the transfer tool 38 employs multipleadjustable headers 40 which for the embodiment shown correspond to thesegments in the mandrel, supported by arms 42 extending from verticalsupport elements 44. Lashing material 46 is laid in the headers toreceive the composite laminate assembly. The composite laminate assembly14 is released from the mandrel 10 by releasing the vacuum on theElastomeric sheet 29. The mandrel and associated support structure andthe transfer tool are then separated and a cure mandrel 48 is invertedover the supported composite laminate assembly as shown in FIG. 7. Thecure mandrel 48 has a profile adapted to receive the formed compositelaminate assembly and is lowered into contact with the compositelaminate assembly 14. The lashing 46 is then attached to the curemandrel 48 to support the composite laminate assembly 14 and the curemandrel is then lifted away from the support structure carrying thecomposite laminate assembly as shown in FIG. 8. The cure mandrel 48 isthen rotated to support the composite laminate assembly 14, the lashings46 removed and the mandrel and composite laminate assembly are insertedinto an autoclave or other heating element for cure of the compositelaminate assembly. A completed part for the wing rib cord is shown inFIG. 10. For the embodiment shown, a single composite laminate assembly14 is employed to mold symmetrically identical parts with the previouslydescribed part line 25 to separate the right hand and left handelements.

The method and tooling described is readily adaptable for high rateproduction employing a line as shown in FIG. 11A. Tray 28 is rollermounted on rails 50. A flat pre-preg composite laminate assembly isprepared, indexed and loaded in the tray 28 on top of an elastomericsheet as previously described. The tray 28 is placed on in-feed table.The pre-preg composite laminate assembly is heated to formingtemperature; for the exemplary embodiment approximately 130 degrees F.The tray 28 is moved along the rails 50 into position under the splineplate 12 which is supported by its actuators 34 from a vertical frame52. The actuators 34 lower the spline plate 12 to the top of the tray28. With the tray sealed to the spline plate, vacuum is applied to thecavity. This pulls the elastomeric sheet 29 and pre-preg compositelaminate assembly 14 up to the segmented forming mandrel 10. Thecomposite laminate assembly wraps around the forming segments, creatinga channel shape. The loading tray 28 is removed to its originalposition.

The actuators 34 lift the spline plate 12, composite laminate assembly14, and elastomeric sheet 29 out of the tray. While still under vacuum,the actuators 34 move to programmed positions to curve the spline plate12 and channel composite laminate assembly 14. While the formedcomposite laminate assembly cools, a shuttle table with the transfertool 38 with matching headers slides into position underneath thecomposite laminate assembly 14 and supports are lifted up to support theformed composite laminate assembly. The vacuum is released, allowing thecomposite laminate assembly 14 to be fully supported by the shuttletable carrying the transfer tool 38. The shuttle table moves the formedcomposite laminate assembly toward the cure tool manipulator.

The cure tool 48, in an inverted attitude, is lowered to mate with theformed composite laminate assembly 14. After the cure tool 48 is seatedinto the formed composite laminate assembly, the formed compositelaminate assembly and elastomer sheet are lashed to the cure tool. Thecure tool 48 and formed composite laminate assembly 14 are lifted out ofthe transfer tool 38 and the cure tool is rotated to the uprightposition. The lashing and elastomeric sheet are removed leaving theformed composite laminate assembly on the cure tool. The cure tool isremoved from the cell. The formed composite laminate assembly is vacuumbagged to the cure tool and sent to an autoclave for cure. While notshown in the drawings, if timing of cure and previously noted processesare approximately equivalent, the autoclave can be located on anextension of the rails allowing the cure tool supports to be railmounted to move the tool and bagged composite laminate assembly directlyinto the autoclave.

An embodiment of the process employing the tooling system of FIG. 11A isdescribed in FIG. 11B. The process is initiated by placing a multi-layercharge of pre-preg material on an elastomeric sheet which lines thesides and bottom of an elongate tray that has vertical side and endwalls in step 1102. The elongate tray rests on a horizontal and flattable. The charge is heated to a forming temperature of approximately130 degrees F. in step 1104. A flexible forming mandrel is placed with aneutral bending axis on its upper surface on top of the charge such thata sealed chamber is created between the mandrel and the elastomer-linedelongate tray in step 1106. A vacuum is applied in the sealed chamber instep 1108 thus pulling the elastomeric sheet and pre-preg charge awayfrom the surface of the elongate tray and around the surface of theforming mandrel. The forming mandrel is lifted from the elongate tray instep 1110 and the forming mandrel is adjusted to the desired contour inthe lengthwise direction while said vacuum is still applied to theelastomeric sheet and composite charge in step 1112. The elongate trayis moved from under the formed charge and mandrel assembly in step 1114and replaced with a transfer tool to support the formed charge in step1116. The vacuum is then released between the charge and the formingmandrel in step 1118 and the charge is transferred to the transfer toolsupport in step 1120. The forming tool is then moved from above thesupported charge in step 1122 and a cure mandrel is placed above thesupported charge in step 11244. The charge is then attached to the curemandrel in step 1126, the cure mandrel and charge are lifted from thesupport tool in step 1128 and the cure tool and charge are rotated onehundred and eighty degrees to an upright orientation in step 1130. Theelastomeric sheet is then removed in step 1132 and the mandrel andcharge are vacuum bagged in the normal manner in step 1134. The chargeis then cured in an autoclave in step 1136.

Alternative embodiments for the tooling a process described provide forvarious structural element shapes and contours with the ability tocreate symmetrical structural pairs. FIG. 12A shows a second exemplarystructural member, a Tee rib 60. The Tee rib is formed from matedinversely symmetrical elements a conventional cord 62 and an invertedcord 64. As shown in FIG. 12B, the conventional and inverted cords arejoined on one leg and for the embodiment shown, the radius gap is filledwith a composite tape pre-formed into a triangular cross-section calleda noodle 66. As shown in FIG. 13, the tooling previously described isadaptable for fabrication of mating elements such as the Tee Rib.Individual flat composite laminate assembly layups or single layups withpart lines are formed to mandrel 10 by evacuating elastomeric baggingmaterials as previously described to provide draping of the compositelaminate assembly elements 14 a, 14 b, 14 c and 14 d. Contouring ofspline plate 12 then simultaneously forms conventional and inverted cordpair 14 a and 14 c as well as the opposite hand conventional andinverted cord pair 14 b and 14 d. Up to four chord angles are made atone time with this mandrel arrangement. Diagonally opposite angles arecombined into tees. The forming block segments 10 d of the mandrel aretall and wide to accommodate the multiple part elements.

FIG. 14 shows an alternative mandrel and composite laminate assemblyarrangement making two chord angles one at a time. This configurationproduces a left hand and right hand pair of either conventional (14 eand 14 f), or inverted (14 g and 14 h) chord angles. The segmentedmandrel employs low profile forming blocks 10 e. Similarly, FIG. 15shows a second alternative making two chord angles 14 i and 14 j or 14 kand 14 l at one time to be assembled into one tee chord. While similarin arrangement to the forming blocks of FIG. 13, forming blocks 10 f inFIG. 15 do not require as much width since individual pairs are formedseparately.

The present method is also applicable to composite structural membershaving a complex center of curvature. As shown in FIGS. 16, 17 and 18,spline plates 70 and 72 which are curved with differing centers ofcurvature reflected by arrows 74 and 76 respectively are incorporated ina saddle as the supporting structure for the shaping surface of theflexible mandrel forming block segments best seen in FIG. 19. Thecurvature of spline plate 70 on the saddle is exaggerated for clarity.One shaping surface 11 of the forming blocks engages one spline platewhile a second shaping surface 13 engages the second spline plate. Thesecond spline surface is provided in the embodiment shown by aprotuberance 75 to provide offset for the neutral axis of the mandrelrelative to the second center of curvature to assure that the drapedcomposite laminate assembly is maintained in tension at all locations.The mandrel forming blocks are connected along a neutral axis 77 for theforming curvature with a steel cable 78 having minimal stretch butlateral flexibility. For the embodiment shown, a set screw 79 in eachsegment forming block prevents movement of the block along the cable. Astraightening cable 80 located central to the forming blocks employstensioning fasteners at its ends to draw the segments together forinitial draping of the flat composite laminate assembly over the mandreland is relaxable by releasing the tension on the fasteners. Alignmentpins 82 located diametrically opposed with respect to the straighteningcable from rigid cable 78 maintain relative alignment of the opposingcorners of the mandrel segments while allowing expansion of the segmentsupon relaxing of the straightening cable. For the embodiment shown,discontinuous zero plies are employed with envelope vacuum bagging toform the composite laminate assembly to the mandrel as described forprevious embodiments.

Once the composite laminate assembly is draped on the mandrel, thestraightening cable tension is released and the mandrel relaxes onto thesaddle spline plates in two directions providing a resultant center ofcurvature perpendicular to the neutral axis as represented bydirectional arrow 84. The mandrel is flexed over the saddle tool whileunder heat and vacuum. The composite laminate assembly is allowed tocool and then removed from flex mandrel and placed on a rigid curemandrel for curing as previously described.

The resulting part with multidimensional curvature, an outboard spar, isshown in FIG. 20. As exemplary of the capability of the tooling andmethod disclosed herein the outboard spar is approximately 131 inches inoverall length 86 with a 4.5 inch flange width 88 and an inside channelwidth varying from an inboard end 90 of 6.6 inches to and outboard end92 of 4.5 inches. A 13 inch cord height 94 can be obtained with thetooling and method described.

The embodiments disclosed herein may be described in the context of anaircraft manufacturing and service method 100 as shown in FIG. 21 and anaircraft 102 as shown in FIG. 22. During pre-production, exemplarymethod 100 may include specification and design 104 of the aircraft 102and material procurement 106. During production, component andsubassembly manufacturing 108 and system integration 110 of the aircraft102 takes place. Thereafter, the aircraft 102 may go throughcertification and delivery 112 in order to be placed in service 114.While in service by a customer, the aircraft 102 is scheduled forroutine maintenance and service 116 (which may also includemodification, reconfiguration, refurbishment, and so on).

Each of the processes of method 100 may be performed or carried out by asystem integrator, a third party, and/or an operator (e.g., a customer).For the purposes of this description, a system integrator may includewithout limitation any number of aircraft manufacturers and major-systemsubcontractors; a third party may include without limitation any numberof venders, subcontractors, and suppliers; and an operator may be anairline, leasing company, military entity, service organization, and soon.

As shown in FIG. 22, the aircraft 102 produced by exemplary method 100may include an airframe 118 with a plurality of systems 120 and aninterior 122. Examples of high-level systems 120 include one or more ofa propulsion system 124, an electrical system 126, a hydraulic system126, and an environmental system 130. Any number of other systems may beincluded. Although an aerospace example is shown, the principles of theembodiments disclosed herein may be applied to other industries, such asthe automotive industry.

Apparatus and methods embodied herein may be employed during any one ormore of the stages of the production and service method 100. Forexample, components or subassemblies corresponding to production process108 may be fabricated or manufactured in a manner similar to componentsor subassemblies produced while the aircraft 102 is in service. Also,one or more apparatus embodiments, method embodiments, or a combinationthereof may be utilized during the production stages 108 and 110, forexample, by substantially expediting assembly of or reducing the cost ofan aircraft 102. Similarly, one or more of apparatus embodiments, methodembodiments, or a combination thereof may be utilized while the aircraft102 is in service, for example and without limitation, to maintenanceand service 116.

Having now described exemplary embodiments in detail as required by thepatent statutes, those skilled in the art will recognize modificationsand substitutions to the specific embodiments disclosed herein. Suchmodifications are within the scope and intent of the present inventionas defined in the following claims.

What is claimed is:
 1. A forming tool for flat pre-impregnated compositelaminate assemblies comprising: a mandrel segmented into a plurality ofcontiguously mounted forming blocks, said forming blocks sized toreceive a draped composite laminate assembly with all portions of thecomposite laminate assembly spaced from at least one shaping surface oneach block; a saddle tool having at least one spline plate receiving theat least one shaping surface of the forming blocks and having a firstcurvature; means for maintaining the draped composite laminate assemblyin contact with the forming blocks; and, a relaxable tensioning cableurging the forming blocks into mutual contact in a first tensionedcondition and relaxable to a released condition while maintainingcontact between adjacent blocks allowing the forming blocks to expand toa desired curvature by relaxing the shaping surface onto the firstcurvature of the spline plate with the mandrel segments extendingtherefrom thereby maintaining the composite laminate assembly intension.
 2. The forming tool as defined in claim 1 wherein the at leastone spline plate comprises a first spline plate and a second splineplate and the at least one shaping surface comprises a first shapingsurface contacting the first spline plate and a second shaping surfacecontacting the second spline plate on the mandrel forming blocks andhaving a second curvature, curvature of said first and second curvaturesdiffering throughout the length of the first spline plate and the secondspline plate.
 3. The forming tool as defined in claim 2 furthercomprising means for restraining the forming blocks at a neutral axis.4. The forming tool as defined in claim 3 wherein the means forrestraining comprises a restraining cable inserted through holes in theforming blocks at the neutral axis.
 5. The forming tool as defined inclaim 4 wherein the cable is constrained in each forming block with aset screw.
 6. The forming tool as defined in claim 3 further comprisingan alignment pin in each forming block substantially diametricallyopposed from the restraining cable around the tensioning cable.
 7. Theforming tool as defined in claim 3 wherein the restraining cable hasminimal stretch and is flexible laterally.
 8. The forming tool asdefined in claim 7 where in the restraining cable is steel.
 9. Theforming tool as defined in claim 2 wherein the forming blocks includeprotuberances received against the second spline plate to offset theneutral axis.
 10. The forming tool as defined in claim 1 wherein themeans for maintaining the draped composite laminate in contact with theforming blocks comprises a vacuum bag.
 11. A multiple axis forming toolfor flat pre-impregnated composite laminate assemblies comprising: amandrel segmented into a plurality of contiguously mounted formingblocks, said forming blocks sized to receive a draped composite laminateassembly with all portions of the composite laminate assembly spacedfrom a first shaping surface and a second shaping surface on each block,the mandrel incorporating a cable restraining the forming blocks on aneutral axis, said forming blocks incorporating protuberances for thesecond shaping surface to offset the neutral axis; a saddle tool havinga first spline plate with a first curvature and a second spline platewith a second curvature said first and second curvatures differingthroughout the length of the first and second plate, said saddle toolreceiving the first shaping surface of the forming blocks on the firstspline plate and receiving the second shaping surface on the secondspline plate; a vacuum bag maintaining the draped composite laminateassembly in contact with the forming blocks; and, a relaxable tensioningcable urging the forming blocks into mutual contact in a first tensionedcondition for initially receiving the draped composite laminate assemblyand relaxable to a released condition while maintaining contact betweenadjacent forming blocks allowing the forming blocks to expand to adesired curvature on the spline plates of the saddle tool by relaxingthe shaping surface onto the first curvature of the first spline plateand second curvature of the second spline plate with the mandrelsegments extending therefrom thereby maintaining the composite laminateassembly in tension.